Don't encourage blindness

I would like to know why people, almost 3.8 thousand years later, still practice the Hammurabi’s code, which establishes “an eye for an eye, a tooth for a tooth”. Haven’t they figured out that no society will ever improve under this rule?
            I guess they don’t know yet that they don’t gain anything by doing it. If they were smart enough, they would realize that it is better for them, as individuals, not to take revenge. Could you imagine what would happen to the world if the entire population – about 7 billion people – takes revenge every time something happens to them? It would create a cycle that would end with even wars and death.
            If the world’s population somehow forgets about this absurd rule, the world would be a better place. Eventually, no one would harm others and half the problems of the world would be eradicated.

"An eye for an eye only ends up making the whole world blind."

Mahatma Gandhi